# # create a mapping of state to abbreviation
# states = {
#     'Oregon':'OR',
#     'Florida':'FL',
#     'California':'CA',
#     'New York':'NY',
#     'Michigan':'MI'
# }
#
# # create a basic set of states and some cities in them
# cities = {
#     'CA':'San Francisco',
#     'MI':'Detroit',
#     'FL':'Jacksonville'
# }
#
# # add some more cities
# cities['NY'] = 'New York'
# cities['OR'] = 'Portland'
#
# # print out some cities
# print('_' * 10)
# print("NY State has: ",cities['NY'])
# print("OR State has: ",cities['OR'])
#
# # print some states
# print('_' * 10)
# print("Michigan's abbreviation is: ",states['Michigan'])
# print("Florida's abbreviation is: ", states['Florida'])
#
# # do it by using the state then cities dict
# print('_' * 10)
# print("Michigan has: ",cities[states['Michigan']])
# print("Florida has: ",cities[states['Florida']])
#
# # print every state abbreviation
# print('_' * 10)
# for state,abbrev in list(states.items()):
#     print(f"{state} is abbreviated {abbrev}")
#
# # print every city in state
# print('_' * 10)
# for abbrev,city in list(cities.items()):
#     print(f"{abbrev} has the city {city}")
#
# # now do both at the same time
# print('_' * 10)
# for state,abbrev in list(states.items()):
#     print(f"{state} state is abbreviated {abbrev}")
#     print(f"and has city {cities[abbrev]}")
#
# print('-' * 10)
# # safely get a abbreviation by state that might not be there
# state = states.get('Texas')
# # print(state)        # None
# # print(not state)    # True
#
# if not state:
#     print("Sorry,no Texas.")
#
# # get a city with a default value
# city = cities.get('TX','Does Not Exist')
# print(f"The city for the state 'TX' is:{city}")
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cities = {
    'sichuan':'chengdu',
    'yunnan':'dali',
    'guizhou':'guiyang',
    'guangdong':'guangzhou'
}

print(cities['sichuan'])

cities['xizang'] = 'lasa'
print(cities)

for province,city in list(cities.items()):
    print(f"{province} has city:{city}")

print(list(cities.items()))

city0 = cities.get('xinjiang','This province does not exist.')
print(city0)

print(list(cities.keys()))
print(list(cities.values()))